Amniotic compositions, such as amniotic membrane and extracts from amniotic membrane obtained from amniotic tissue derived from mammals, such as humans, pigs, or horses, include biological growth factors. Amniotic membrane is a biological membrane that lines the inner surface of the amniotic cavity and comprises a simple, cuboidal epithelium, a thick basement membrane, and an avascular mesenchymal layer containing hyaluronic acid. Amniotic compositions are known to reduce inflammation, fibrovascular ingrowth, and to facilitate epithelialization in animal models. Amniotic membrane is believed to play a role in the scarless wound healing process in a fetus (Tseng, S.-C.-G., et al., “Suppression of Transforming Growth Factor-Beta Isoforms, TGF-β Receptor Type II, and Myofibroblast Differentiation in Cultured Human Corneal and Limbal Fibroblasts by Amniotic Membrane Matrix,” J. Cell. Physiol., 179: 325-335 (1999)).
Fetal membrane, including the amnion (amniotic membrane) and chorion has been used in surgeries, documented as early as 1910 with the use by Davis on burned and ulcerated skin (Davis, J. W., “Skin Transplantation With a Review of 550 cases at the Johns Hopkins Hospital,” Johns Hopkins Med. J, 15: 307 (1910). Beginning in 1973, Trelford and associates reported other uses of amnion, including, for example, a use to replace pelvic peritoneum, use on full-thickness skin wounds, use to cover exposed deep surfaces in pedicle graft procedures, use as a graft over the surgical defect of total glossectomy, and in the prevention of meningocerebral adhesions following head injury (See Trelford and Trelford-Sauder, “The Amnion in Surgery, Past and Present,” Am. J. Obstet. Gynecol., 134: 833 (1979)).
Amniotic compositions have been used for treatment of injured corneal tissue. For example, amniotic membrane transplantation has been used for ocular surface reconstruction for acute chemical and thermal burns (Kim, J.-C., and Tseng, S.-C.-G., “A Transplantation of Preserved Human Amniotic Membrane for Surface Reconstruction in Severely Damaged Rabbit Corneas,” Cornea 14(5): 473-484 (1995)). The surgical technique of suturing is used to secure the transplanted amniotic membrane to a tissue surface, either internally or externally (Id. at 475). For example, in the case of injured corneal tissue, whether amniotic membrane is used is used as a permanent graft or as a temporary patch, sutures are used to secure the membrane on a patient's eye at a major operating room.
Although, for example, amniotic membrane may be sutured to an ocular surface, it may not be possible to bring patients under critical care to the operating room for the needed eye surgery. Thus, a need exists for a device to facilitate the use of amniotic membrane for treatment of injured or diseased tissue, such as, for example, chemically or thermally burned corneal tissue, without the requirement of suturing the membrane in place.
Suturing has also been used to fasten amniotic membrane to a culture insert, such as a silicone ring, for use in culturing cells. The making of culture inserts by the suturing method, however, is time-consuming. Thus a need exists for an efficient method of making culture inserts.